You can replace damaged of missing scripts in your main system boot partition, or you can replace that entire partition with a "factory original" backup copy. You can zero the /var/local partition if it was filled from indexing too many books. These things are documented in multiple places, but I recommend the "simple debricking" and "select boot" threads.

well, still questions.

i suppose the mmcblk0p1.img of 350mb is the backup, isn't it ?
then ,i should boot in diag mode, export usb, copy rumme.sh, and data.tar.gz

but, where should i put this mmcblk0p1?
copy to kindle, or to my pc, and where?